1. Field of the Invention
The invention relates to a web centerwinder for receiving and winding a web material and its method for winding. Specifically, the invention relates to a web central winder and method for receiving and winding web material sequentially on one of at least two fixed shafts.
2. Brief Description of the Background Art
“Centerwinding” is a term used in the film, foil, or paper industries to describe the process of receiving a web material as it is produced and turning the web material on a core or shaft in order to wind a roll of the web material. Centerwinding winds a roll by driving the roll from the center as opposed to surface winding. A web of film, foil, or paper is typically wound on a cardboard or fiber core that is secured on a mandrel shaft or from end supports. The roll of web material is removed and shipped to an end user.
A centerwinder can use a single core, shaft, or spindle, supported in a frame and driven by a motor. Commonly, multiple shafts are provided, keeping one in standby ready to accept the constantly flowing web as the other core, shaft, or spindle completes winding a full roll of web material.
An example occurs in the plastics industry where a polymer film is generated by blown film production methods and wound on a cardboard or fibrous core. Rolls of film can be produced wherein, for example, 1,500 linear feet or more of film is wound into a single roll of film. The roll of film can then be shipped to a plastic bag manufacturer. The plastic bag manufacturer can subsequently print the film and produce bags from the film.
Increased operating speeds of continuous web systems led the industry to adopt turret-type centerwinders. Turret-type centerwinders commonly incorporate two or more shafts mounted to a rotatable turret assembly. The turret has a winding position and an unloading position. The turret revolves to place a core into the feed of a web material while simultaneously positioning the full roll in a position for unloading or removal from the turret.
Turret-type centerwinders include a lay-on roll to smooth the film and meter or remove air between layers of film. Such centerwinders have additional mechanisms to automate the web transfer from a full roll to a new core. Shortcomings of these “turret winders” include (1) extra equipment complexity and higher equipment costs, (2) the winding shafts located on a rotatable turret impede the transfer of the web and roll stability, and (3) inherent difficulties in unloading and recording a shaft located on a rotatable turret.
U.S. Pat. No. 2,256,082 to Feurt discloses a paper converting machine. This early example of a winding device was concerned with minimizing the loss of time due to breaking of “thin stock” or web material. The invention of this patent required control of the stopping and starting of the machine for each individual roll so that no unwanted breakages in the web material occur.
U.S. Pat. No. 4,678,133 to Suzuki discloses an automatic cutting and winding apparatus for a web-like material such as a film. This patent discloses a turret-type automatic cutting and winding apparatus. The turret is typical of those used in the industry and involves a turret with a motor, a gear box, and related apparatus that can swing a full roll of film away from the production apparatus and place an empty core into the web feed without disruption of the production of web material.
The industry lacks a centerwinder that receives and rolls a web material without the use of complex apparatus such as a turret and permits continued winding without interruption of the manufacture of the web material. The industry further lacks a turretless centerwinder with an automatic transfer mechanism. Also, the industry lacks a turretless centerwinder with an efficient shaft handling mechanism.